MULTISCALE MODELING OF NON LINEAR BEHAVIOURIN VARIOUS COMPOSITE MATERIALS

摘要

Composite materials are more and more used in aeronautical applications. The study of the strength ofthese structures is a multiscale problem. The aim of this work is to model several structures (using thefinite element method) reinforced by composite materials taking into account all pertinent levels.Various techniques can be used to model the macroscopic composite behaviour. They are respectivelybased on* The use of a classical macroscopic model which is developed and identified using experimentalresults.* The use of a ``macroscopic multiscale`` model which is derived from scales transitions and `` keepsin memory `` the microscopic scale. The composite is thus described at the structural scale as anhomogenous medium. This of modeling is called ``sequential approach``.* The resolution of the constitutive laws at the local scale using different change of scale methods.These kind of methods are called ``integrated approaches``.Different approaches are compared, in structural calculations, in terms of computational cost,macroscopic results and local quantities. The first example is devoted to the modelling of an integrallybladed ring reinforced by a SiC/Ti composite. The second example is devoted to the modelling of astructure reinforced by a polymer matrix composite.